Allergan is recalling one lot of birth-control pills because the first four pills in a 28-pill pack are inactive, placing women at risk of pregnancy.

One lot of Taytulla physician sample packs (marked lot #5620706 Exp. May 2019) contained the out-of-order pills, the company said. It learned about the error from a doctor who reported it.

The blister packs should have contained pink capsules with oral contraceptive hormones for the first 24 days, followed by four days of maroon capsules without hormones. Reversing the order of the pills could have gone unnoticed by women taking them. Missing even a few days of the hormones could lead to unintended pregnancy if taken at the wrong time over 28 days.

In a statement, Allergan said it is notifying customers by recall letter. It also encouraged patients to contact their doctors. A call to Allergan seeking more information about how many pill packs were recalled was not immediately answered.

Allergan's stock fell 2 percent Monday morning. The company has been buffeted for months by bad publicity related to its unsuccessful deal with an Native American tribe to shield itself from a patent challenge.

In January it cut 1,400 jobs to prepare for generic competition to its best-selling product, Restasis eye drops.